Merkel cell carcinoma (MCC) is a rare and aggressive form of skin cancer caused by the Merkel cell polyomavirus.

Patients who do not respond to immune checkpoint inhibitors have a median survival of just four months, highlighting the need for new treatment options.

In patients without TP53 mutations, viral proteins activate MDM2 to block p53 function, preventing normal cell death.

In a Phase Ib/II trial led by Michael K. Wong, M.D., Ph.D., researchers evaluated navtemadlin, a targeted therapy against MDM2, in MCC patients without TP53 mutations.

The study enrolled 31 patients that previously received anti-PD-1/L1 therapies, randomly assigned to different dose levels.

The putative recommended Phase II dose achieved a 25% confirmed overall response rate and a 63% disease control rate.

This dose level was well-tolerated, with fewer dose reductions and longer treatment duration than higher doses.

Grade 3/4 treatment-related adverse events were seen in 68% of patients across all dose levels, while hematologic side effects were most common.

The findings suggest this therapeutic approach warrants further study for patients with MCC.

Wong will present updated findings on June 5.

Source: MD Anderson Cancer Center